High-temperature-resistant flux-cored wire containing rare earth elements and method for preparing same

Abstract

The application relates to the technical field of welding materials, and particularly discloses a high-temperature-resistant flux-cored wire containing rare earth elements and a preparation method thereof. The high-temperature-resistant flux-cored wire containing rare earth elements comprises a wire sheath and a core; the core comprises the following raw materials: dehydrated rutile, dehydrated potassium feldspar, zircon sand, metal chromium powder, metal nickel powder, electrolytic manganese, ferrotitanium, aluminiferous iron, potassium cryolite, potassium titanate, sodium titanate, iron powder, yttrium-based iron alloy powder, atomized ferrosilicon, chromium-iron nitride, bismuth oxide, an additive, and the balance of reduced iron powder; the additive is a mixture of zirconium-iron alloy, ferrotitanium alloy and aluminum-magnesium alloy. The application introduces a specific alloy additive into the core to protect the transition of the rare earth yttrium, optimizes the welding performance of the yttrium and multiple components in cooperation, matches the 253MA heat-resistant steel, adjusts the components of the molten slag and the electric arc, and reasonably processes the technology, so that the welding quality of the wire is improved.

Description

Technical Field

[0001] This application relates to the field of welding materials technology, and more specifically, it relates to a high-temperature flux-cored welding wire containing rare earth elements and its preparation method. Background Technology

[0002] 253MA heat-resistant steel is a high-chromium-nickel austenitic heat-resistant steel with excellent high-temperature oxidation resistance and high-temperature strength. It is widely used in key components of high-temperature equipment such as power plant boilers, petrochemical heating furnaces, and waste incinerators. These components must withstand high-temperature oxidation, thermal fatigue, and stress corrosion during long-term high-temperature service, thus requiring extremely high performance from welded joints.

[0003] Existing welding wires used for welding 253MA heat-resistant steel are mostly solid wires or ordinary flux-cored wires, which suffer from problems such as coarse weld grains, insufficient high-temperature strength, and poor fatigue resistance. Under high-temperature conditions, welded joints are prone to cracking, oxidation failure, and other malfunctions, affecting the lifespan and safety of equipment. To improve the high-temperature resistance of flux-cored wires, existing technologies often involve adding alloying elements such as Cr, Ni, Mo, and W to the flux core, utilizing the solid solutions or intermetallic compounds formed to strengthen the weld microstructure. For example, patent application CN113579551A discloses a 253MA heat-resistant stainless steel flux-cored welding wire and its preparation method. The 253MA heat-resistant stainless steel flux-cored welding wire uses commonly used 304 stainless steel strip or 304L stainless steel strip as the cladding layer. The mass percentage of each alloy component in the core is as follows: natural rutile 15-20%, quartz 5-8%, zircon sand 3-7%, high-temperature alumina 2-6%, sodium fluoride 2-4%, magnesia 2-4%, iron sand 2-4%, bismuth oxide 0.5-1%, metallic chromium powder 17-25%, metallic nickel powder 8-15%, low-carbon ferromanganese 2-4%, mixed rare earth 5-10%, micro-carbon ferrochrome 6-12%, mixed nitride powder 6-10%, ferromolybdenum 0-2%, and the balance is reduced iron powder, which is 0 or other percentage content, used to make up 100%. The mixed rare earth component is a mechanical mixture of rare earth ferrosilicon and cerium oxide. This application document, by strictly controlling the mass percentage of mixed rare earth elements in the flux core, manages the rare earth element content in the deposited metal within a specific range. This transforms elongated, needle-like, or bulky oxides and sulfides in the weld into spherical oxides or sulfides, while simultaneously refining the grain size in the weld and improving the high-temperature mechanical properties of the weld joint. However, due to their extremely high chemical reactivity, rare earth elements are prone to premature high-temperature oxidation (i.e., high-temperature burn-off) during the flux core storage stage or in the early stages of the weld pool when protection is lacking. A large amount of these rare earth elements are converted into stable oxides, leading to a significant loss of the effective rare earth components in the flux core, rendering its original functions of refining grain size and purifying grain boundaries ineffective. Furthermore, the generated oxide particles disrupt the balance of the original deoxidation, slag formation, and arc stabilization system of the flux core, interfering with the normal function of the deoxidizer, altering the viscosity of the slag, and potentially causing uneven agglomeration of the flux core powder, affecting the quality of the welding wire formation. Consequently, welding problems become prominent: metallic rare earth elements cannot stably transition to the weld, failing to exert their core strengthening and protective functions, resulting in coarse weld grains and a significant decrease in high-temperature crack resistance and oxidation resistance. Summary of the Invention

[0004] To improve welding quality, this application provides a high-temperature resistant flux-cored welding wire containing rare earth elements and its preparation method.

[0005] In the first aspect, this application provides a high-temperature resistant flux-cored welding wire containing rare earth elements, employing the following technical solution. A high-temperature resistant flux-cored welding wire containing rare earth elements includes a wire sheath and a flux core. The flux core comprises the following raw materials in parts by weight: 15-19 parts dehydrated rutile, 7-8.5 parts dehydrated potassium feldspar, 2-4 parts zircon sand, 13.5-16 parts metallic chromium powder, 6.5-8.5 parts metallic nickel powder, 3-4 parts electrolytic manganese, 1-1.8 parts ferrotitanium, 1-1.8 parts ferroaluminum, 3-3.8 parts potassium cryolite, 2-2.8 parts potassium titanate, 3-3.8 parts sodium titanate, 2-3.5 parts iron concentrate, 0.9-1.7 parts yttrium-based ferroalloy powder, 10-11.5 parts atomized ferrosilicon, 3.8-4.5 parts ferrochromium nitride, 0-0.4 parts bismuth oxide, 1.4-1.9 parts additives, and the balance being reduced iron powder. The additive is a mixture of zirconium ferroalloy, titanium ferroalloy and aluminum-magnesium alloy.

[0006] By adopting the above technical solution, this application introduces an additive composed of zirconium ferroalloy, titanium ferroalloy, and aluminum-magnesium alloy into the flux core. This additive preferentially combines with oxygen, effectively preventing premature high-temperature oxidation and burn-off of rare earth yttrium in the yttrium-based ferroalloy during storage or early welding, ensuring a stable transition of yttrium to the weld. The synergistic effect of yttrium with components such as chromium, nickel, atomized ferrosilicon, and ferrochrome nitride in the flux core not only refines the weld grains and purifies grain boundaries, reducing hot cracking sensitivity, but also forms a dense and stable composite oxide film, significantly improving the tensile strength and oxidation resistance of the weld. At the same time, it ensures a high degree of matching between the weld composition and 253MA heat-resistant steel, avoiding performance gradients in the weld joint. In addition, components such as dehydrated rutile, potassium feldspar, and potassium titanate in the flux core regulate slag viscosity and arc stability. Combined with a reasonable preparation process, this results in good wire formability, no defects such as porosity and cracks during welding, excellent slag removal, and improved welding quality.

[0007] Preferably, the mass ratio of the zirconium-iron alloy, the titanium-iron alloy, and the aluminum-magnesium alloy is (1.8-2.2):(1.8-2.2):(0.9-1.1).

[0008] By adopting the above technical solutions, aluminum-magnesium alloy exhibits the strongest deoxidation activity and the fastest reaction rate. It can preferentially capture free oxygen in the environment and trace amounts of oxygen in the flux core and outer sheath during the initial welding stage, rapidly reducing the oxygen partial pressure of the system and achieving rapid deoxidation, thus constructing an initial antioxidant barrier for rare earth yttrium. Zirconium-iron alloy and titanium-iron alloy possess moderate deoxidation activity and a more sustained reaction, continuously participating in the deoxidation reaction during the high-temperature stage of welding. This compensates for the volatile nature of deoxidation products from aluminum-magnesium alloy, achieving long-term deoxidation and preventing secondary oxidation of rare earth yttrium in the high-temperature environment of the molten pool, ensuring its stable transition to the weld. Under precise proportions, the rapid deoxidation of aluminum-magnesium alloy and the long-term deoxidation of zirconium-iron and titanium-iron alloys complement each other sequentially, avoiding the byproduct residue problems caused by incomplete or excessive deoxidation of a single alloy, and achieving precise control of oxygen content throughout the entire welding cycle.

[0009] Secondly, the alumina and magnesium oxides generated from the deoxidation of aluminum-magnesium alloys are high-melting-point oxides, which can serve as heterogeneous nucleation sites for weld grain refinement, initially inhibiting grain growth. The titanium oxide generated from the deoxidation of titanium-iron alloys not only further refines the grains but also synergistically interacts with components such as potassium titanate and sodium titanate in the flux core to regulate the structure and viscosity of the slag, improving arc stability. The zirconium oxide generated from the deoxidation of titanium-iron alloys possesses excellent high-temperature stability and can form a dense composite oxide film with the aforementioned oxides, filling the defects of single oxide films and significantly improving the oxidation resistance and high-temperature strength of the weld. The precise matching of the proportions of these three components optimizes the content and distribution of the three deoxidation products, avoiding weld inclusion defects caused by an excess of any one type of product, and achieving the dual effects of grain refinement and oxide film strengthening through the synergistic effect between the products.

[0010] Furthermore, zirconium in zirconium-iron alloys and titanium in titanium-iron alloys can synergistically work with rare earth yttrium to further purify the weld grain boundaries and reduce hot cracking sensitivity; the light metal elements in aluminum-magnesium alloys can improve the toughness of the weld and complement heat-resistant elements such as chromium and nickel, ensuring the weld performance matches that of 253MA heat-resistant steel; and the precise proportion design ensures the overall activity of the additives and the compatibility of the slag-regulating components such as dehydrated rutile and potassium feldspar in the flux core, avoiding the influence of excessively strong or weak additive activity on slag viscosity and arc stability, thereby ensuring the formability and slag removal of the welding process and reducing defects such as porosity and cracks.

[0011] In summary, this precise ratio maximizes the core role of each alloy while avoiding the limitations of a single component through ratio control, ultimately achieving effective protection of rare earth yttrium, improving weld performance, and enhancing welding process stability.

[0012] Preferably, the additive is obtained by mixing zirconium-iron alloy, titanium-iron alloy and aluminum-magnesium alloy and then plasma treating the mixture.

[0013] By adopting the above technical solution, and utilizing the high-temperature, high-energy environment and protective atmosphere of plasma, the surface cleaning, active site activation, and micro-interface pre-composite of the three alloy particles are achieved. Furthermore, the temporal synergy of rapid deoxidation of aluminum-magnesium alloy and long-term deoxidation of zirconium-titanium alloy is enhanced, along with the functional synergy of deoxidation product composite reinforcement. This ensures precise control of oxygen partial pressure throughout the welding cycle, effectively preventing premature oxidation and burn-off of rare earth yttrium. It also improves the uniformity of the overall composition and activity of the additives, avoiding particle agglomeration, proportion deviation, and secondary oxidation problems that easily occur with mechanical mixing, ensuring batch stability. Simultaneously, the uniformly active particles formed after treatment can be precisely matched with the slag control components in the flux core, optimizing slag viscosity and arc stability, reducing weld porosity, inclusions, and other defects. Moreover, the deoxidation products can be uniformly dispersed to form a dense composite oxide film and exert a grain refinement effect, significantly improving the tensile strength, oxidation resistance, and high-temperature service stability of the weld.

[0014] Preferably, the preparation method of the auxiliary agent includes the following steps: (1) The aluminum-magnesium alloy was subjected to plasma treatment to obtain activated powder; (2) Tetrabutyl zirconate and ferroacetylacetone are added to anhydrous ethanol, and sodium borohydride is added and stirred to obtain a coating solution; the activated powder is immersed in the coating solution and stirred for 2 hours under argon protection at 55-65℃, filtered and dried to obtain the coating powder; the coating powder is vacuum sintered at 800-900℃ for 3-4 hours to obtain zirconium iron alloy coated aluminum magnesium alloy; the mass of the tetrabutyl zirconate, ferroacetylacetone, sodium borohydride and anhydrous ethanol is (3.5-4.5):(2.2-2.8):(1.0-1.2):(22-28); the solid-liquid ratio of the activated powder to the coating solution is 1:(8-10) g / mL; (3) Tetraethyl titanate and iron carbonyl compound in a molar ratio of (2.0-2.5):1 are mixed as a gas source, and titanium-iron alloy is coated on the surface of zirconium-iron alloy coated aluminum-magnesium alloy by plasma-enhanced chemical vapor deposition to obtain the additive.

[0015] By employing the above technical solution, the surface activity of the aluminum-magnesium alloy is first activated by plasma treatment, removing oxide films and impurities to provide a clean and highly reactive substrate for subsequent coating. Then, through liquid-phase coating and vacuum sintering, zirconium-iron alloy is uniformly and densely coated onto the aluminum-magnesium alloy surface, preventing premature oxidation or volatilization of the aluminum-magnesium alloy due to its high reactivity, and achieving a tight bond between zirconium-iron and aluminum-magnesium. Finally, PECVD technology is used to precisely coat the surface with titanium-iron alloy, further optimizing the compositional uniformity and structural density of the additives. This core-shell structure achieves a gradient function: rapid deoxidation of the aluminum-magnesium core, long-term deoxidation of the zirconium-iron intermediate layer, and synergistic strengthening of the titanium-iron outer layer. This effectively protects the rare earth yttrium from premature oxidation and allows the deoxidation products of the three alloys to be uniformly dispersed, forming a dense composite oxide film and refining the weld grains. It also facilitates synergy between the additives and other components of the flux core, improving the tensile strength, oxidation resistance, and high-temperature service stability of the weld.

[0016] Preferably, the preparation method of the additive further includes step (4), specifically: oxygen is first introduced into the additive obtained in step (3), followed by vinyl acetate vapor for passivation treatment.

[0017] By adopting the above technical solution, oxygen and vinyl acetate can form a dense and easily decomposable passivation film on the surface of the additive. This effectively isolates the contact between air and the active metal elements on the surface of the additive, ensuring that the synergistic function of rapid deoxidation of aluminum and magnesium and long-term deoxidation of zirconium and titanium can still be exerted during welding, fully protecting rare earth yttrium from premature oxidation and burn-off. Furthermore, because the passivation film can be rapidly decomposed and volatilized under the high temperature environment of welding, it will not leave residues to form weld inclusions or affect the molten pool reaction, avoiding adverse effects on the distribution of deoxidation products, the formation of composite oxide film, and the grain refinement effect. At the same time, the passivation treatment can improve the storage stability and anti-caking ability of the additive, reduce particle agglomeration, and ensure the uniformity of its mixing with other components of the flux core. In addition, the passivation film does not affect the compatibility of the additive with the slag control components in the flux core, and can stably maintain the slag viscosity and arc stability during welding. Ultimately, it helps the welding wire form a defect-free weld in high-temperature welding conditions, continuously strengthening the tensile strength, oxidation resistance, and long-term service reliability of the weld.

[0018] Preferably, the mass ratio of the welding wire sheath to the flux core is (74-77):(23-26).

[0019] By adopting the above technical solution, it is possible to ensure that the outer sheath provides sufficient structural strength and forming stability for the welding wire, preventing deformation and cracking during drawing, feeding, and welding. Simultaneously, it supplements the weld with appropriate amounts of heat-resistant and corrosion-resistant elements such as nickel and chromium, forming elemental synergy with the flux core components. Furthermore, it ensures sufficient filling of the flux core, allowing its core functional components, such as deoxidizing alloys, rare earth yttrium, and slag modifiers, to fully function, achieving efficient deoxidation, grain refinement, composite oxide film formation, and slag viscosity control. This avoids functional weakening due to insufficient flux core content or impacting the structural stability and wire feeding smoothness due to excessively high flux core content. This ratio ensures a deep match between the structural support and elemental supplementation of the outer sheath and the functional enhancement and process optimization of the flux core, guaranteeing a high degree of compatibility between the weld composition and 253MA heat-resistant steel, reducing performance gradients in the weld joint, and improving arc stability, slag removal, and forming properties during the welding process, thereby reducing defect risks.

[0020] Preferably, the outer sheath of the welding wire is made of 304L steel strip with a thickness of 0.4 mm and a width of 10 mm. By weight percentage, it includes: carbon < 0.04%, silicon < 0.3%, manganese 1-2.5%, sulfur < 0.02%, nickel 8.0-9.0%, chromium 18-19%, and the balance being iron.

[0021] By adopting the above technical solution, 304L steel strip, as the outer sheath of the welding wire, can reduce the adverse effects of harmful impurities during the welding process due to its high-quality composition characteristics of low carbon, low silicon, and low sulfur, and avoid the generation of welding defects such as intergranular corrosion, porosity, and cracks. The corrosion-resistant and heat-resistant elements such as nickel and chromium contained in it can not only form a synergistic effect with the relevant components of the flux core to ensure that the weld composition is highly matched with the target heat-resistant steel and avoid performance gradients in the weld joint, but also rely on its own excellent high-temperature resistance and corrosion resistance to further improve the long-term service stability of the weld. At the same time, the reasonable steel strip specification design can ensure that the flux core is filled evenly and sufficiently, which helps to optimize the welding wire forming effect. Combined with the control of slag viscosity and arc stability by the flux core components, it can further improve the slag removal and arc stability of the welding process.

[0022] Preferably, the purity of the electrolytic manganese powder, metallic nickel powder, and metallic chromium powder is greater than 99.9%.

[0023] Preferably, the Si content in the atomized ferrosilicon powder is ≥45%.

[0024] Preferably, the particle size of the core is 200-300 mesh.

[0025] Secondly, this application provides a method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements, employing the following technical solution. A method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements includes the following steps: The flux core is filled into the outer sheath of the welding wire, and after multiple drawing processes, it is annealed to obtain the finished welding wire.

[0026] By adopting the above technical solution, the preparation method, through a simple process of flux filling, multi-pass drawing and annealing, not only ensures the forming accuracy of the welding wire and the density and uniformity of the flux core, but also improves the toughness of the welding wire and the adaptability to the welding process, making it suitable for industrial mass production, while providing a guarantee for the high-temperature performance and welding reliability of the weld.

[0027] In summary, this application has the following beneficial effects: 1. This application improves the welding quality of welding wire by introducing specific alloying agents into the flux core to protect the stable transition of rare earth yttrium, synergistically optimizing the weld performance with multiple components and matching 253MA heat-resistant steel, and by controlling the composition of slag and arc and using reasonable processes.

[0028] 2. This application prepares an additive by mixing zirconium iron, titanium iron, and aluminum-magnesium alloy and then treating it with plasma. By utilizing its high temperature and high energy and protective atmosphere, it achieves deoxidation synergy, improves the uniformity and batch stability of the additive, and is compatible with the composition of flux-cored slag, optimizes the welding process and the performance of slag and arc, and reduces weld defects. At the same time, through the dispersion of deoxidation products and grain refinement, it significantly improves the overall performance of the weld and its high-temperature service stability.

[0029] 3. The additives in this application are prepared by plasma-activated aluminum-magnesium alloy, liquid-phase coating and vacuum sintering to form a zirconium-iron alloy coating layer, and PECVD coating of titanium-iron alloy to obtain core-shell structure products. This achieves gradient deoxidation and synergistic strengthening functions, which not only protects rare earth yttrium from premature oxidation, but also allows the deoxidation products to be evenly dispersed and the grains to be refined, helping it to synergistically improve the overall performance of the weld and high-temperature service stability with other components of the flux core. Detailed Implementation

[0030] The present application will be further described in detail below with reference to preparation examples, embodiments and comparative examples.

[0031] Unless otherwise specified, the raw materials used in the preparation examples, embodiments, and comparative examples of this application are all commercially available.

[0032] Preparation Example 1 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: Zirconium-iron alloy (58-62 wt% zirconium content, ≥99.5% purity), titanium-iron alloy (FeTi70 type) (≥99.5% purity), and aluminum-magnesium alloy (MTCMT-AlMg3) (≥99.5% purity) were pulverized and sieved to obtain powders with a particle size of 50-150 μm. The alloy particles were then placed in anhydrous ethanol and ultrasonically cleaned at 100W for 15 min. The cleaned alloy particles were then placed in a vacuum drying oven and dried at 55℃ and a vacuum degree ≤-0.09 MPa for 2.5 h. Next, 20 g of the pretreated zirconium-iron alloy, 20 g of titanium-iron alloy, and 10 g of aluminum-magnesium alloy were added to a mixer and stirred at 250 r / min for 40 min under nitrogen protection to obtain a mixture. The mixture was then placed back into a vacuum drying oven and dried at 50℃ and a vacuum degree ≤-0.09 MPa for 2 h to obtain the additive.

[0033] Preparation Example 2 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: Zirconium-iron alloy with a zirconium content of 58-62 wt% and a purity of ≥99.5%, titanium-iron alloy (FeTi70 type) with a purity of ≥99.5%, and aluminum-magnesium alloy (MTCMT-AlMg3) with a purity of ≥99.5% were pulverized and sieved to obtain powders with a particle size of 50-150 μm. The alloy particles were then placed in anhydrous ethanol and ultrasonically cleaned at 100W for 15 min. The cleaned alloy particles were then placed in a vacuum drying oven and dried at 55℃ and a vacuum degree ≤-0.09 MPa for 2.5 h. Next, 18 g of the pretreated zirconium-iron alloy, 22 g of titanium-iron alloy, and 11 g of aluminum-magnesium alloy were added to a mixer and stirred at 250 r / min for 40 min under nitrogen protection to obtain a mixture. The mixture was then placed back into a vacuum drying oven and dried at 50℃ and a vacuum degree ≤-0.09 MPa for 2 h to obtain the additive.

[0034] Preparation Example 3 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: Zirconium-iron alloy with a zirconium content of 58-62 wt% and a purity of ≥99.5%, titanium-iron alloy (FeTi70 type) with a purity of ≥99.5%, and aluminum-magnesium alloy (MTCMT-AlMg3) with a purity of ≥99.5% were pulverized and sieved to obtain powders with a particle size of 50-150 μm. The alloy particles were then placed in anhydrous ethanol and ultrasonically cleaned at 100W for 15 min. The cleaned alloy particles were then placed in a vacuum drying oven and dried at 55℃ and a vacuum degree ≤-0.09 MPa for 2.5 h. Next, 22 g of the pretreated zirconium-iron alloy, 18 g of titanium-iron alloy, and 9 g of aluminum-magnesium alloy were added to a mixer and stirred at 250 r / min for 40 min under nitrogen protection to obtain a mixture. The mixture was then placed back into a vacuum drying oven and dried at 50℃ and a vacuum degree ≤-0.09 MPa for 2 h to obtain the additive.

[0035] Preparation Example 4 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: Zirconium-iron alloy (58-62 wt% zirconium content, ≥99.5% purity), titanium-iron alloy (FeTi70 type, ≥99.5% purity), and aluminum-magnesium alloy (MTCMT-AlMg3, ≥99.5% purity) were respectively pulverized and sieved to obtain powders with a particle size of 50-150 μm. The alloy particles were then placed in anhydrous ethanol and ultrasonically cleaned at 100W for 15 min. The cleaned alloy particles were then placed in a vacuum drying oven and dried at 55℃ and a vacuum degree ≤-0.09 MPa for 2.5 h. Finally, the pretreated 20... 20g of zirconium-iron alloy, 20g of titanium-iron alloy, and 10g of aluminum-magnesium alloy were added to a mixer and stirred at 250r / min for 40min under nitrogen protection to obtain a mixture. The mixture was then sent to a low-temperature plasma treatment instrument, where argon gas with a purity ≥99.9% and a flow rate of 1.5L / min was used as the plasma working gas and protective gas. The mixture was treated at 100W power and 100℃ for 25min to obtain a final mixture. The final mixture was then placed in a vacuum drying oven and dried at 50℃ and a vacuum degree ≤-0.09MPa for 2h to obtain the additive.

[0036] Preparation Example 5 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: (1) Aluminum-magnesium alloy (MTCMT-AlMg3) with a purity ≥99.5% was crushed and sieved to obtain powder with a particle size of 50-150μm. Then it was placed in a plasma treatment device, and argon gas with a purity ≥99.9% and a flow rate of 25sccm was introduced as a protective atmosphere. The vacuum degree was controlled at 40Pa, and the powder was treated for 30min at a power of 150W to obtain activated powder. (2) Add 40g tetrabutyl zirconate and 25g iron acetylacetone to 250g anhydrous ethanol, stir for 50min at 30℃ and 450r / min, then add 11g sodium borohydride and continue stirring for 35min to obtain a coating solution; immerse 10g activated powder in 90mL of coating solution, stir at 550r / min for 2h at 60℃ and 35sccm argon protective atmosphere; filter after the reaction, vacuum dry the filter cake at 110℃ for 5.5h to obtain coated powder; place the coated powder in a vacuum sintering furnace, heat to 850℃ at a heating rate of 10℃ / min, hold for 3.5h, and cool to room temperature to obtain zirconium iron coated aluminum magnesium alloy; (3) 2.3 mol of tetraethyl titanate and 1 mol of iron pentacarbonyl were mixed and used as the plasma-enhanced chemical vapor deposition gas source. The zirconium iron-coated aluminum magnesium alloy was placed in the plasma-enhanced chemical vapor deposition reaction chamber. The vacuum was first evacuated to ≤5 Pa and the substrate was preheated to 350 °C. Then the gas source was introduced and the gas source flow rate was controlled at 45 sccm and the reaction gas pressure at 65 Pa. The deposition was carried out at 250 W power for 120 min. During the deposition process, the substrate rotation speed was kept at 10 r / min. After the deposition was completed, the additive was naturally cooled to room temperature.

[0037] Preparation Example 6 This preparation example is basically the same as preparation example 5, except that it also includes step (4) putting the obtained additive into a vacuum passivation furnace, introducing oxygen at 0.008 MPa, reacting at 70°C for 1 h; and then passing it through 5 wt% vinyl acetate vapor for continuous adsorption for 45 min for passivation treatment.

[0038] Preparation Example 7 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: (1) Aluminum-magnesium alloy (MTCMT-AlMg3) with a purity ≥99.5% was crushed and sieved to obtain powder with a particle size of 50-150μm. Then it was placed in a plasma treatment device, and argon gas with a purity ≥99.9% and a flow rate of 25sccm was introduced as a protective atmosphere. The vacuum degree was controlled at 40Pa, and the powder was treated for 30min at a power of 150W to obtain activated powder. (2) Add 35g tetrabutyl zirconate and 22g iron acetylacetone to 220g anhydrous ethanol, stir for 50min at 30℃ and 450r / min, then add 10g sodium borohydride and continue stirring for 35min to obtain a coating solution; immerse 10g activated powder in 100mL of coating solution, stir at 550r / min for 2h under an argon protective atmosphere of 35sccm at 55℃; filter after the reaction, and vacuum dry the filter cake at 110℃ for 5.5h to obtain coated powder; place the coated powder in a vacuum sintering furnace, raise the temperature to 800℃ at a heating rate of 10℃ / min, hold for 4h, and cool to room temperature to obtain zirconium iron coated aluminum magnesium alloy; (3) 2 mol of tetraethyl titanate and 1 mol of iron pentacarbonyl were mixed and used as the plasma-enhanced chemical vapor deposition gas source. The zirconium iron-coated aluminum magnesium alloy was placed in the plasma-enhanced chemical vapor deposition reaction chamber. The vacuum was first evacuated to ≤5 Pa and the substrate was preheated to 350 °C. Then the gas source was introduced and the gas source flow rate was controlled at 45 sccm and the reaction gas pressure at 65 Pa. The deposition was carried out at 250 W power for 120 min. During the deposition process, the substrate rotation speed was kept at 10 r / min. After the deposition was completed, the additive was naturally cooled to room temperature.

[0039] (4) The obtained additive is placed in a vacuum passivation furnace, oxygen at 0.008 MPa is introduced, and the reaction is carried out at 70°C for 1 h; then passivation is carried out by continuous adsorption of 5 wt% vinyl acetate vapor for 45 min.

[0040] Preparation Example 8 This preparation example discloses a method for preparing an auxiliary agent, specifically including the following steps: (1) Aluminum-magnesium alloy (MTCMT-AlMg3) with a purity ≥99.5% was crushed and sieved to obtain powder with a particle size of 50-150μm. Then it was placed in a plasma treatment device, and argon gas with a purity ≥99.9% and a flow rate of 25sccm was introduced as a protective atmosphere. The vacuum degree was controlled at 40Pa, and the powder was treated for 30min at a power of 150W to obtain activated powder. (2) Add 45g tetrabutyl zirconate and 28g iron acetylacetone to 280g anhydrous ethanol, stir for 50min at 30℃ and 450r / min, then add 12g sodium borohydride and continue stirring for 35min to obtain a coating solution; immerse 10g activated powder in 80mL of coating solution, stir at 550r / min for 2h at 65℃ and 35sccm argon protective atmosphere; filter after the reaction, vacuum dry the filter cake at 110℃ for 5.5h to obtain coated powder; place the coated powder in a vacuum sintering furnace, heat to 900℃ at a heating rate of 10℃ / min, hold for 3h, and cool to room temperature to obtain zirconium iron coated aluminum magnesium alloy; (3) 2.5 mol of tetraethyl titanate and 1 mol of iron pentacarbonyl were mixed and used as the plasma-enhanced chemical vapor deposition gas source. The zirconium iron-coated aluminum magnesium alloy was placed in the plasma-enhanced chemical vapor deposition reaction chamber. First, the vacuum was evacuated to ≤5 Pa and the substrate was preheated to 350 °C. Then, the gas source was introduced and the gas source flow rate was controlled at 45 sccm and the reaction gas pressure at 65 Pa. The deposition was carried out at 250 W power for 120 min. During the deposition process, the substrate rotation speed was kept at 10 r / min. After the deposition was completed, the additive was naturally cooled to room temperature.

[0041] (4) The obtained additive is placed in a vacuum passivation furnace, oxygen at 0.008 MPa is introduced, and the reaction is carried out at 70°C for 1 h; then passivation is carried out by continuous adsorption of 5 wt% vinyl acetate vapor for 45 min.

[0042] Example 1 This embodiment provides a high-temperature resistant flux-cored welding wire containing rare earth elements, including a wire sheath and a flux core. The wire sheath is made of 304L steel strip with a thickness of 0.4 mm and a width of 10 mm. Its composition meets the following requirements: carbon < 0.04%, silicon < 0.3%, manganese 1%-2.5%, sulfur < 0.02%, phosphorus < 0.02%, nickel 8.0%-9.0%, chromium 18%-19%, and the balance is iron.

[0043] The core comprises the following components: 17g dehydrated rutile, 8g dehydrated potassium feldspar, 3g zircon sand, 15g metallic chromium powder, 7.5g metallic nickel powder, 3.5g electrolytic manganese, 1.5g ferrotitanium, 1.5g aluminum ferroalloy, 3.5g potassium cryolite, 2.5g potassium titanate, 3.5g sodium titanate, 3g iron concentrate, 1.2g yttrium-based ferroalloy powder (yttrium content 18-22%), 11g atomized ferrosilicon (Si content ≥45%), 4g ferrochrome nitride, 0.2g bismuth oxide, 1.5g additives, and 12g reduced iron powder; wherein the purity of electrolytic manganese powder, metallic nickel powder, and metallic chromium powder is greater than 99.9%, the additives are those obtained from Preparation Example 1, and the core powder has a particle size of 200-300 mesh with 60 mesh being fully passable.

[0044] This embodiment also provides a method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements, including the following steps: The flux-cored powders in the above proportions are mixed evenly under argon protection, then placed in a dryer and baked at 200℃ for 2 hours. After baking, they are naturally cooled to room temperature. 75g of 304L steel strip is rolled into a U-shaped groove structure using a forming machine, and 25g of flux powder is filled into the U-shaped groove. The steel strip with the flux-cored core is sent to a drawing machine for drawing. After every 3 drawing cycles, the welding wire is placed in an annealing furnace and held at 200℃ for 1.5 hours under nitrogen protection. The drawing-annealing process is repeated until the welding wire is finally drawn to a diameter of 1.2mm to obtain the finished welding wire.

[0045] Example 2 This embodiment is basically the same as Example 1, except that the additives used are those obtained in Preparation Example 2.

[0046] Example 3 This embodiment is basically the same as Example 1, except that the additives used are those obtained in Preparation Example 3.

[0047] Example 4 This embodiment is basically the same as Example 1, except that the additives used are those obtained in Preparation Example 4.

[0048] Example 5 This embodiment is basically the same as Example 1, except that the additive used is the one obtained in Preparation Example 5.

[0049] Example 6 This embodiment is basically the same as Example 1, except that the additive used is the one obtained in Preparation Example 6.

[0050] Example 7 This embodiment provides a high-temperature resistant flux-cored welding wire containing rare earth elements, including a wire sheath and a flux core. The wire sheath is made of 304L steel strip with a thickness of 0.4 mm and a width of 10 mm. Its composition meets the following requirements: carbon < 0.04%, silicon < 0.3%, manganese 1%-2.5%, sulfur < 0.02%, phosphorus < 0.02%, nickel 8.0%-9.0%, chromium 18%-19%, and the balance is iron.

[0051] The core comprises the following components: 19g dehydrated rutile, 8.5g dehydrated potassium feldspar, 4g zircon sand, 16g metallic chromium powder, 8.5g metallic nickel powder, 4g electrolytic manganese, 1.8g ferrotitanium, 1.8g aluminum ferroalloy, 3.8g potassium cryolite, 2.8g potassium titanate, 3.8g sodium titanate, 3.5g iron concentrate, 1.7g yttrium-based ferroalloy powder, 11.5g atomized ferrosilicon, 4.5g ferrochromium nitride, 0.4g bismuth oxide, 1.9g additives, and 2.5g reduced iron powder. The purity of the electrolytic manganese powder, metallic nickel powder, and metallic chromium powder is greater than 99.9%. The additives are those obtained in Preparation Example 7. The core powder has a particle size of 200-300 mesh, with all particles passing through a 60-mesh sieve.

[0052] This embodiment also provides a method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements, including the following steps: The flux-cored powders in the above proportions were mixed evenly under argon protection, then placed in a dryer and baked at a constant temperature of 200℃ for 2 hours. After baking, the mixture was allowed to cool naturally to room temperature. 74g of 304L steel strip was rolled into a U-shaped groove structure using a forming machine, and 26g of flux powder was filled into the U-shaped groove. The steel strip with the flux-cored core was then fed into a drawing machine for drawing. After every 3 drawing cycles, the welding wire was placed in an annealing furnace and held at 200℃ for 1.5 hours under nitrogen protection. The drawing-annealing process was repeated until the welding wire was finally drawn to a diameter of 1.2mm to obtain the finished welding wire.

[0053] Example 8 This embodiment provides a high-temperature resistant flux-cored welding wire containing rare earth elements, including a wire sheath and a flux core. The wire sheath is made of 304L steel strip with a thickness of 0.4 mm and a width of 10 mm. Its composition meets the following requirements: carbon < 0.04%, silicon < 0.3%, manganese 1%-2.5%, sulfur < 0.02%, phosphorus < 0.02%, nickel 8.0%-9.0%, chromium 18%-19%, and the balance is iron.

[0054] The core comprises the following components: 15g dehydrated rutile, 7g dehydrated potassium feldspar, 2g zircon sand, 13.5g metallic chromium powder, 6.5g metallic nickel powder, 3g electrolytic manganese, 1g ferrotitanium, 1g ferroaluminum, 3g potassium cryolite, 2g potassium titanate, 3g sodium titanate, 2g iron concentrate, 0.9g yttrium-based ferroalloy powder, 10g atomized ferrosilicon, 3.8g ferrochromium nitride, 1.4g additives, and 24.9g reduced iron powder; wherein the purity of electrolytic manganese powder, metallic nickel powder, and metallic chromium powder is greater than 99.9%, the additives are those obtained from Preparation Example 8, and the core powder has a particle size of 200-300 mesh with 60 mesh being fully passable.

[0055] This embodiment also provides a method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements, including the following steps: The flux-cored powders in the above proportions were mixed evenly under argon protection, then placed in a dryer and baked at 200℃ for 2 hours. After baking, they were allowed to cool naturally to room temperature. 77g of 304L steel strip was rolled into a U-shaped groove structure using a forming machine, and 23g of flux powder was filled into the U-shaped groove. The steel strip with the flux-cored core was then fed into a drawing machine for drawing. After every 3 drawing cycles, the welding wire was placed in an annealing furnace and held at 200℃ for 1.5 hours under nitrogen protection. The drawing-annealing process was repeated until the welding wire was finally drawn to a diameter of 1.2mm to obtain the finished welding wire.

[0056] Comparative Example 1 This comparative example is basically the same as Example 1, except that the core contains the following components: 17g dehydrated rutile, 8g dehydrated potassium feldspar, 3g zircon sand, 15g metallic chromium powder, 7.5g metallic nickel powder, 3.5g electrolytic manganese, 1.5g ferrotitanium, 1.5g aluminum ferroalloy, 3.5g potassium cryolite, 2.5g potassium titanate, 3.5g sodium titanate, 3g iron concentrate, 1.2g yttrium-based ferroalloy powder (yttrium content 18-22%), 11g atomized ferrosilicon (Si content ≥45%), 4g ferrochrome nitride, 0.2g bismuth oxide, and 13.5g reduced iron powder; wherein the purity of electrolytic manganese powder, metallic nickel powder, and metallic chromium powder is greater than 99.9%, and the core powder particle size is 200-300 mesh with 60 mesh being fully passable.

[0057] Comparative Example 2 This comparative example is basically the same as Example 1, except that the core contains the following components: 17g dehydrated rutile, 8g dehydrated potassium feldspar, 3g zircon sand, 15g metallic chromium powder, 7.5g metallic nickel powder, 3.5g electrolytic manganese, 1.5g ferrotitanium, 1.5g ferroaluminum, 3.5g potassium cryolite, 2.5g potassium titanate, 3.5g sodium titanate, 3g iron concentrate, and yttrium-based ferroalloy powder (yttrium content 18-22%). 0.2g, atomized ferrosilicon (Si content ≥45%) 11g, ferrochrome nitride 4g, bismuth oxide 0.2g, additives 1.5g and reduced iron powder 12g; wherein, the purity of electrolytic manganese powder, metallic nickel powder and metallic chromium powder is greater than 99.9%, the additive is a zirconium-iron alloy with a particle size of 50-150μm, a zirconium content of 58-62wt% and a purity ≥99.5%, and the core powder has a particle size of 200-300 mesh with 60 mesh fully passable.

[0058] Comparative Example 3 This comparative example is basically the same as Example 1, except that the core contains the following components: 17g dehydrated rutile, 8g dehydrated potassium feldspar, 3g zircon sand, 15g metallic chromium powder, 7.5g metallic nickel powder, 3.5g electrolytic manganese, 1.5g ferrotitanium, 1.5g aluminum ferroalloy, 3.5g potassium cryolite, 2.5g potassium titanate, 3.5g sodium titanate, 3g iron concentrate, and yttrium-based ferroalloy powder (yttrium content 18-22%). 1.2g, atomized ferrosilicon (Si content ≥45%) 11g, ferrochrome nitride 4g, bismuth oxide 0.2g, additives 1.5g and reduced iron powder 12g; wherein, the purity of electrolytic manganese powder, metallic nickel powder and metallic chromium powder are all greater than 99.9%, the additives are titanium-iron alloy (FeTi70 type) with a particle size of 50-150μm and a purity of ≥99.5%, and the core powder has a particle size of 200-300 mesh with 60 mesh fully passable.

[0059] Comparative Example 4 This comparative example is basically the same as Example 1, except that the core contains the following components: 17g dehydrated rutile, 8g dehydrated potassium feldspar, 3g zircon sand, 15g metallic chromium powder, 7.5g metallic nickel powder, 3.5g electrolytic manganese, 1.5g ferrotitanium, 1.5g ferroaluminum, 3.5g potassium cryolite, 2.5g potassium titanate, 3.5g sodium titanate, 3g iron concentrate, and yttrium-based ferroalloy powder (yttrium content 18-22%). 0.2g, atomized ferrosilicon (Si content ≥45%) 11g, ferrochrome nitride 4g, bismuth oxide 0.2g, additives 1.5g and reduced iron powder 12g; wherein, the purity of electrolytic manganese powder, metallic nickel powder and metallic chromium powder are all greater than 99.9%, the additives are aluminum-magnesium alloy (MTCMT-AlMg3) with a particle size of 50-150μm and a purity ≥99.5%, and the core powder has a particle size of 200-300 mesh with 60 mesh fully passable.

[0060] Performance testing Testing standards: The welding wires prepared in Examples 1-8 and Comparative Examples 1-4 were welded on a 253MA test plate at a welding current of 180A, a welding voltage of 28V, a welding shielding gas of CO2, and a shielding gas flow rate of 15L / min. The following tests were performed, and the welding groove and weld seam samples were selected according to GB4334.5-90 and GB / T17854-1999 standards.

[0061] The chemical composition of the deposited metal was tested after welding. The chemical composition of the deposited metal was tested in accordance with GB / T17854-1999 standard, and the test results are recorded in Table 1.

[0062] Mechanical properties: Tensile strength and elongation at break were tested according to GB / T228-2021 standard, and the test results are recorded in Table 2.

[0063] Splash performance: Tested according to GB / T25776-2010 standard, and the test results are recorded in Table 2.

[0064] High-temperature oxidation resistance: Tested according to GB / T10124-2017 standard, and the test results are recorded in Table 2.

[0065] Table 1. Weld metal deposition data (%) in Examples 1-8 and Comparative Examples 1-4

[0066] Table 2 Performance test data of Examples 1-8 and Comparative Examples 1-4

[0067] Referring to Tables 1 and 2, and in conjunction with Example 1 and Comparative Examples 1-4, it can be seen that Example 1, by using a composite additive configured in a specific ratio, successfully solved the oxidation and burn-off problem of rare earth yttrium during high-temperature welding, achieving a stable transition of yttrium to the weld. Furthermore, through the grain refinement and grain boundary purification effects of yttrium on the weld, as well as the synergistic effect with other heat-resistant alloy components in the flux core, the overall performance of the weld was significantly optimized. Comparative Example 1, without any additives, saw yttrium easily oxidized at high temperatures, failing to effectively transition to the weld. The weld performance relied solely on the basic components of the flux core without substantial improvement. The single-component additives used in Comparative Examples 2-4 failed to create a synergistic protective effect of rapid and long-term deoxidation to ensure a stable transition of yttrium. They also disrupted the uniformity and stability of the original slag system in the flux core, introducing additional defects. Consequently, their weld performance was not only far inferior to Example 1, but also lower than that of Comparative Example 1 without additives due to inclusions and uneven deoxidation.

[0068] Referring to Tables 1 and 2, and in conjunction with Examples 1 and 4, it can be seen that the additive used in Example 1 only underwent mechanical mixing, resulting in limited component dispersion uniformity and activity. This failed to fully leverage the synergistic deoxidation effect, leading to a mediocre weld transition effect for rare earth yttrium and insufficient optimization of weld performance. In Example 4, the additive underwent plasma treatment in addition to mechanical mixing. This treatment activated the active sites on the additive surface, strengthened the interfacial bonding and uniformity between components, significantly improved the rapid and long-term synergistic deoxidation capabilities, effectively ensured the stable transition of yttrium, and thus significantly improved the overall weld performance through the synergistic effect of yttrium and other alloy components in the flux core, while also enhancing the process stability of the welding process.

[0069] Referring to Tables 1 and 2, and in conjunction with Examples 1 and 5, it can be seen that the composite additive prepared by mechanical mixing in Example 1, although it can initially exert a synergistic deoxidation effect, has limited component dispersion uniformity and interfacial bonding force, resulting in insufficient protection of rare earth yttrium. The transition efficiency and stability of yttrium are average, and the weld performance is not optimal. The additive in Example 5 forms a core-shell structure through plasma activation, liquid phase coating and vacuum sintering, and plasma-enhanced chemical vapor deposition, achieving a gradient function of "rapid deoxidation - long-term deoxidation - synergistic strengthening". It can more comprehensively avoid the oxidation and burn-off of yttrium throughout the welding cycle, ensuring its stable transition to the weld. Furthermore, through the grain refinement and grain boundary purification effects of yttrium, it deeply synergizes with the heat-resistant alloy components in the flux core, significantly optimizing the overall weld performance, while also improving the slag stability and process adaptability during the welding process.

[0070] Referring to Tables 1 and 2, and in conjunction with Examples 5 and 6, it can be seen that the additive in Example 5, through plasma activation, liquid phase coating and vacuum sintering, and plasma-enhanced chemical vapor deposition processes, forms a core-shell structure, which can achieve gradient deoxidation and effectively protect the stable transition of rare earth yttrium to the weld. Example 6 adds passivation treatment to the additive based on the core-shell structure. This treatment can isolate air during the additive storage stage, prevent premature oxidation of its surface active metals, and can quickly decompose at the high temperature of welding without producing residual impurities, further ensuring the integrity of the core-shell structure and the synergistic deoxidation efficiency, making the transition stability of yttrium better, and the synergistic effect with the heat-resistant alloy components in the flux core more complete. Finally, the overall performance of the weld and the stability and reliability of the welding process are better.

[0071] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high-temperature resistant flux-cored welding wire containing rare earth elements, characterized in that, The welding wire includes an outer sheath and a flux core. The flux core comprises the following raw materials in parts by weight: 15-19 parts dehydrated rutile, 7-8.5 parts dehydrated potassium feldspar, 2-4 parts zircon sand, 13.5-16 parts metallic chromium powder, 6.5-8.5 parts metallic nickel powder, 3-4 parts electrolytic manganese, 1-1.8 parts ferrotitanium, 1-1.8 parts ferroaluminum, 3-3.8 parts potassium cryolite, 2-2.8 parts potassium titanate, 3-3.8 parts sodium titanate, and 2 parts iron concentrate. -3.5 parts, 0.9-1.7 parts of yttrium-based iron alloy powder, 10-11.5 parts of atomized ferrosilicon, 3.8-4.5 parts of ferrochromium nitride, 0-0.4 parts of bismuth oxide, 1.4-1.9 parts of additives, and the balance being reduced iron powder; the additives are a mixture of zirconium ferroalloy, titanium ferroalloy and aluminum-magnesium alloy; the preparation method of the additives includes the following steps: (1) obtaining activated powder by plasma treatment of aluminum-magnesium alloy; (2) taking zirconium Tetrabutyl zirconate and ferroacetylacetone were added to anhydrous ethanol, and sodium borohydride was added. The mixture was stirred to obtain a coating solution. The activated powder was immersed in the coating solution and stirred for 2 hours under argon protection at 55-65℃. The mixture was then filtered and dried to obtain the coating powder. The coating powder was vacuum sintered at 800-900℃ for 3-4 hours to obtain zirconium iron alloy coated aluminum magnesium alloy. The mass ratio of tetrabutyl zirconate, ferroacetylacetone, sodium borohydride and anhydrous ethanol was (3.5-4.5):(2.2-2.8):(1.0-1.2):(22-28). The solid-liquid ratio of the activated powder to the coating solution was 1:(8-10) g / mL. (3) Tetraethyl titanate and iron carbonyl compound were mixed in a molar ratio of (2.0-2.5):1 as a gas source. The titanium iron alloy was coated on the surface of the zirconium iron alloy coated aluminum magnesium alloy by plasma-enhanced chemical vapor deposition to obtain the additive.

2. The high-temperature resistant flux-cored welding wire containing rare earth elements according to claim 1, characterized in that, The preparation method of the additive further includes step (4), which is: oxygen is first introduced into the additive obtained in step (3) and then vinyl acetate vapor is introduced for passivation treatment.

3. The high-temperature resistant flux-cored welding wire containing rare earth elements according to claim 1, characterized in that, The mass ratio of the welding wire sheath to the flux core is (74-77):(23-26).

4. The high-temperature resistant flux-cored welding wire containing rare earth elements according to claim 1, characterized in that, The outer sheath of the welding wire is made of 304L steel strip with a thickness of 0.4mm and a width of 10mm. By weight percentage, it includes: carbon <0.04%, silicon <0.3%, manganese 1-2.5%, sulfur <0.02%, nickel 8.0-9.0%, chromium 18-19%, and the balance is iron.

5. The high-temperature resistant flux-cored welding wire containing rare earth elements according to claim 1, characterized in that, The purity of the electrolytic manganese, nickel powder, and chromium powder is greater than 99.9%.

6. The high-temperature resistant flux-cored welding wire containing rare earth elements according to claim 5, characterized in that, The Si content in the atomized ferrosilicon powder is ≥45%.

7. A method for preparing a high-temperature resistant flux-cored welding wire containing rare earth elements according to any one of claims 1-6, characterized in that, The process includes the following steps: filling the outer sheath of the welding wire with flux, drawing it through multiple passes, and then annealing it to obtain the finished welding wire.

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